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Preventing Condensation in Venting

Stokehold
Stokehold Member Posts: 43
If a 3" PVC vent for a high efficiency power vented water heater or furnace must travel through the unconditioned space of a home (attic), what is the recommended type of insulation to wrap the pipe to minimize condensation? Is it better to use a foil backed foam wrap, fiberglass or pre slit foam sections?

Comments

  • NY_Rob
    NY_Rob Member Posts: 1,370
    Is it a condensing appliance?
    Check with the manufacturers install guidelines, but my condensing boiler install manual was pretty clear on PVC vent insulation:
    "DO NOT thermally insulate the exhaust vent or intake pipes. "
  • ChrisJ
    ChrisJ Member Posts: 11,974
    NY_Rob said:

    Is it a condensing appliance?
    Check with the manufacturers install guidelines, but my condensing boiler install manual was pretty clear on PVC vent insulation:
    "DO NOT thermally insulate the exhaust vent or intake pipes. "

    I had looked into this for my dad as when it's -20F out the fresh air intake sweats like you would've believe. I believe the instructions to his recommended insulating the intake.

    What does the manufacturer of your boiler want someone to do under these conditions, just let it drip all over?

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment